I [..] used the command

$ sudo apt-get install ros-distro-barrett-hand

did you literally type in ros-distro-barrett-hand for the name of the package? If so, that is not what is meant there: the idea is that you replace distro with the name of your ROS distribution. Seeing as you state you installed ROS Kinetic, that would be:

sudo apt-get install ros-kinetic-barret-hand

However, having written that, be aware that you can only use apt to install additional packages if you've installed your base ROS with apt. If you built ROS from source (which may be the case, seeing as you mention an RPi 4), you cannot do this.

I also tried cloning the barrett_hand repository from github and used the "make" command inside the cloned directory and I get the error "no makefile found".

Two things:

1. ROS packages are actually CMake packages. So you cannot use make directly with them. You'd have to at least run cmake first, but:
2. Catkin packages require a certain nr of steps to build them from source in your workspace. Simply cloning them and then running catkin_make (or make) won't work. Refer to #q252478 for an example of that workflow.

Note again that if you've built ROS from source, you'll need a slightly different workflow (involving rosinstall_generator), but I won't go into that now until you describe what you used.